High Efficiency Rare Earth Element Biomining with Systems Biology Guided Engineering of <i>Gluconobacter oxydans</i>

Abstract

Abstract The global demand for critical rare earth elements (REE) is rising 1 with the increase in demand for sustainable energy technologies like wind turbines 2,3 , electric vehicles 2,3 , and high efficiency lighting 4 . Current processes for producing REE require high energy inputs and can produce disproportionate amounts of hazardous waste. Biological methods for REE production are a promising solution to this problem. In earlier work we identified the most important genetic mechanisms contributing to the REE-bioleaching capability of Gluconobacter oxydans B58 5 . Here we have targeted two of these mechanisms to generate a high-efficiency bio-mining strain of G. oxydans . Disruption of the phosphate-specific transport system through a clean deletion of pstS constitutively turns on the phosphate starvation response, yielding a much more acidic biolixiviant, and increasing bioleaching by up to 30%. Coupling knockout of pstS with the over-expression of the mgdh membrane-bound glucose dehydrogenase gene, results in up to 73% improvement of REE-bioleaching.